Question

A quadratic trend equation was estimated from monthly sales of trucks in the United States from July 2006 to July 2011. The estimated trend is y(t) = 106 + 1.03 t + 0.048 t^2, where y(t) units are in thousands. From this trend, how many trucks would be sold in July 2012? (A) About 308,419 (B) About 524,889 (C) About 436,982 (D) About 223,831

Answer 1

Answer: (C) 436,982

Step-by-step explanation:

We can find the amount of trucks that would be sold in July 2012 by replacing the number of the month in the quadratic trend equation. They tell us the equation was estimated from July 2006 so this month would be the t=0, now for the month we are looking for this would be t=73 (we have 73 months from July 2006 until July 2012). So

$y(t)=106+1.03(73)+0.048(73)^{2} =436.982$